1. Field of the Invention
The invention relates to a transmission, and more particularly, to a transmission having a breather structure.
2. Description of the Related Art
Japanese Patent Application Publication No. 2008-75850 (JP-A-2008-75850), for example, describes one example of a transmission.
In JP-A-2008-75850, when the temperature of hydraulic fluid in an automatic transmission is high, the level of the hydraulic fluid rises due to air bubbles mixing in with the hydraulic fluid, as well as expansion of the hydraulic fluid. As a result, when the hydraulic fluid is agitated by a rotating element, it may leak from a breather plug. With the transmission described in JP-A-2008-75850, control is used to prevent the hydraulic fluid from leaking. However, this control may not always be able to sufficiently prevent hydraulic fluid (i.e., fluid) from leaking.